There are numerous instances where there is desired a view of a scene that corresponds to a view which is difficult or impossible to achieve directly. One important instance of this is in video conferencing.
In video conferencing, it is advantageous for creating a feeling of intimacy between participants at different stations for them to establish and maintain eye contact with one another during a conversation.
In practice, this is difficult. Generally, to preserve eye contact between two participants in a teleconference both the camera recording the speaker and the local monitor reproducing for viewing an image of the remote listener need to be positioned on the same optical axis, so as to have the speaker look simultaneously into the camera and at the listener in the monitor. However, the camera and the monitor cannot both physically be on a common straight optical axis without one blocking the other.
In the past, expedients such as the use of a half-mirror oriented at 45 degrees in the gaze direction and the positioning of the camera and the mirror orthogonally with respect to the mirror have been used to achieve this end. However, this expedient is awkward and sacrifices both light from the monitor and light to the camera.
The invention aims at a different solution.